PARIS (Reuters) -- Prime Minister Francois Fillon says France will press for "strong sanctions" against Iran at the United Nations, as time is running out for a political solution to the standoff over Iran’s nuclear ambitions.

Iranian President Mahmud Ahmadinejad has said Tehran is ready to send its enriched uranium abroad in exchange for more highly enriched fuel to produce medical isotopes.

But the launch of a satellite rocket on February 3 has fuelled western fears that Tehran is planning to build a nuclear weapon, despite its assurances it seeks only to generate electricity.

"The Iranian government has not wanted to accept our offer of dialogue. It has instead rushed forward headlong. So the moment has come to act," Fillon told a dinner of the French Jewish association Crif.

"I think it's not too late to use the political process to stop Iran from acquiring a nuclear military capacity, but I acknowledge that time is pressing," he said.

"We are going to seek the adoption of a new resolution at the United Nations incorporating strong sanctions and the European Union must also accept its responsibilities," he said.

Fillon's comments echo remarks from French President Nicolas Sarkozy who said last month that the United Nations had to adopt strong measures against Iran to persuade it to start meaningful negotiations over its nuclear program.